Feet
Mouth
Nose
Spine
Strongylocentrotus
Animalia
Purpuratus
Echinoderms
Both intertidal area and subtidal areas
Intertidal area only
On the beach
Subtidal area only
Sea cucumbers
Small fish
Other sea urchins
Algae
Because sea urchins have large numbers of eggs
Because sea urchins have large numbers of relatively big eggs
Because the eggs make great omlettes
Because a sea urchin's egg is relatively big
Pentamerous
Dome
Porcupine
Toothpick